files

R Base 3.6.2

These functions provide a low-level interface to the computer's file system.

Syntax

file.create(&#8230;, showWarnings = TRUE)
file.exists(&#8230;)
file.remove(&#8230;)
file.rename(from, to)
file.append(file1, file2)
file.copy(from, to, overwrite = recursive, recursive = FALSE,
          copy.mode = TRUE, copy.date = FALSE)
file.symlink(from, to)
file.link(from, to)
Sys.junction(from, to)

Arguments

Parameter	Description
`…, file1, file2`	character vectors, containing file names or paths.
`from, to`	character vectors, containing file names or paths. For file.copy and file.symlink and Sys.junction to can alternatively be the path to a single existing directory.
`overwrite`	logical; should existing destination files be overwritten?
`showWarnings`	logical; should the warnings on failure be shown?
`recursive`	logical. If to is a directory, should directories in from be copied (and their contents)? (Like cp -R on POSIX OSes.)
`copy.mode`	logical: should file permission bits be copied where possible?
`copy.date`	logical: should file dates be preserved where possible? See Sys.setFileTime.

Return Value

These functions return a logical vector indicating which operation succeeded for each of the files attempted. Using a missing value for a file or path name will always be regarded as a failure. If showWarnings = TRUE, file.create will give a warning for an unexpected failure.

Details

The … arguments are concatenated to form one character string: you can specify the files separately or as one vector. All of these functions expand path names: see path.expand. file.create creates files with the given names if they do not already exist and truncates them if they do. They are created with the maximal read/write permissions allowed by the ‘umask’ setting (where relevant). By default a warning is given (with the reason) if the operation fails. file.exists returns a logical vector indicating whether the files named by its argument exist. (Here ‘exists’ is in the sense of the system's stat call: a file will be reported as existing only if you have the permissions needed by stat. Existence can also be checked by file.access, which might use different permissions and so obtain a

Examples

Example

# NOT RUN {
cat("file A\n", file = "A")
cat("file B\n", file = "B")
file.append("A", "B")
file.create("A") # (trashing previous)
file.append("A", rep("B", 10))
if(interactive()) file.show("A") # -> the 10 lines from 'B'
file.copy("A", "C")
dir.create("tmp")
file.copy(c("A", "B"), "tmp")
list.files("tmp") # -> "A" and "B"
setwd("tmp")
file.remove("A") # the tmp/A file
file.symlink(file.path("..", c("A", "B")), ".")
                     # |--> (TRUE,FALSE) : ok for A but not B as it exists already
setwd("..")
unlink("tmp", recursive = TRUE)
file.remove("A", "B", "C")
# }